clang/test/CodeGenCXX/copy-elision.cpp

   1 // RUN: %clang_cc1 -std=c++14 -triple x86_64-unknown-unknown-gnu -emit-llvm -O1 -o - %s | FileCheck %s
   2
   3 template <class T> T test() {
   4   return T();
   5 }
   6
   7 struct A {
   8   A();
   9   A(A &);
  10   A(int);
  11   operator int();
  12 };
  13
  14 // FIXME: There should be copy elision here.
  15 // CHECK-LABEL: define{{.*}} void @_Z4testI1AET_v
  16 // CHECK:       call void @_ZN1AC1Ev
  17 // CHECK-NEXT:  call noundef i32 @_ZN1AcviEv
  18 // CHECK-NEXT:  call void @_ZN1AC1Ei
  19 // CHECK-NEXT:  call void @llvm.lifetime.end
  20 template A test<A>();
  21
  22 struct BSub {};
  23 struct B : BSub {
  24   B();
  25   B(B &);
  26   B(const BSub &);
  27 };
  28
  29 // FIXME: There should be copy elision here.
  30 // CHECK-LABEL: define{{.*}} void @_Z4testI1BET_v
  31 // CHECK:       call void @_ZN1BC1Ev
  32 // CHECK:       call void @_ZN1BC1ERK4BSub
  33 // CHECK-NEXT:  call void @llvm.lifetime.end
  34 template B test<B>();